((doc,win)=>{
  const docEl = doc.documentElement,
      recalc = () => {
          let clientWidth = docEl.clientWidth;
          docEl.style.fontSize = (clientWidth / 1920) * 100 + "px";
      };
  if(doc.addEventListener){
      doc.addEventListener("DOMContentLoaded", recalc, !1);
      win.addEventListener("resize", recalc, !1);
  }
})(document,window)